Conventional electrical boxes for high voltage components are typically secured to a wall support member such as a stud. Installing such a conventional box in an old work or retrofit situation therefore requires that a stud be located within the wall, a cavity formed in the wall covering next to the stud, and nails, screws, or similar fasteners driven through from the box into the stud to secure the electrical box to the wall. The entire electrical box is positioned within the wall so that the front face of the box is essentially even with the wall surface. In such a retrofit application, the wall cavity is substantially equal to the depth of the stud or approximately 3.5-inches thereby affording plenty of depth to accommodate the conventional box within the wall cavity.
Unfortunately, there are some applications, such as recreational vehicles (RVs) and block walls, in which the walls are typically much shallower than for a conventional wall framed with studs. A cavity formed in such a wall in a retrofit situation is substantially shallow and will not accommodate a conventional electrical box.
What is needed therefore is an electrical box that can be mounted within a shallow wall cavity while still accommodating large electrical components such as ground fault circuit interrupters (GFCIs).